This project will test the feasibility of conducting a full-scale multi-center randomized clinical trial to determine: - Whether treatment of hypertension will prevent deterioration of renal function in patients with hypertensive nephropathy - Whether the choice of antihypertensive agent affects the rate of progression of hypertensive renal disease - Whether the course of hypertensive renal disease in the Black hypertensive can be altered by the use of more affordable antihypertensive therapy - Whether the increased prevalence of progressive renal disease in the Black hypertensive is related to a significant prevalence of nonhypertensive underlying renal disease - The mechanisms required to recruit large numbers of Black hypertensives at risk for hypertensive renal damage into a clinical trial to investigate preventive therapies This center has assembled a group of experienced clinical investigators with research interest in Clinical Pharmacology, Nephrology, Endocrinology, Cardiology, the Social Sciences and extensive clinical trial experience in studies of Black hypertensives. We propose a double-blind parallel study which would include a control group that would be referred back to community resources for treatment. Antihypertensive therapy in subjects treated by study personnel will consist of double-blinded random assignment of patients to either a thiazide diuretic, converting enzyme inhibitor, or a calcium channel blocker. These represent the classes of antihypertensives either most likely to be utilized in treating Black hypertensives or where there are data which suggest a renal protective effect. Additional agents will be added in open fashion until diastolic blood pressure is equal to or less than 85mm Hg. A renal biopsy will be performed in all subjects at entry and a repeat biopsy performed in those who show a reduction in GFR renal function inspite of good blood pressure control. It is crucial to establish that loss of renal function is not due to causes other than hypertension which potentially may be treatable. Renal function will be monitored by measuring GFR before randomization and then annually.